RiaSTAP vs. Conventional Transfusion in Patients Having Heart Valve Surgery

Overview

Heart surgery involving valve replacement often involves the use of the heart-lung machine for over 90 minutes, and bleeding tendency is frequently seen. Conventionally, platelet transfusion has been the primary therapy to treat bleeding after this type of procedure. More recently, perioperative supplementation of purified fibrinogen (RiaSTAP, CSL Behring) was shown to reduce bleeding and blood product use (plasma or platelets) after heart surgery. The objective of this trial is to demonstrate the clinical equivalency and economic utility of using fibrinogen concentrate, RiaSTAP for the mitigation of post-operative bleeding in patients in lieu of platelet transfusion. Purified fibrinogen concentrate has been approved by FDA, and it has been used for the treatment of acute bleeding episodes in patients with low fibrinogen due to hereditary causes (e.g., afibrinogenemia). Compared to the transfusion of platelets which may be associated with volume overload, bacterial/viral infection, immunological effects and excess blood clotting, purified fibrinogen has several advantages. First, it contains no liquid plasma allowing for low volume infusion. Several viral inactivation/reduction steps are used to prepare the fibrinogen concentrate, increasing its viral safety. No antibodies or white blood cells are contained in the fibrinogen concentrate; therefore transfusion reactions are rare. Although platelet transfusion is widely used after heart surgery, there has been no randomized study to endorse this practice. In this study, patients undergoing heart valve replacement will be randomized to receive either platelet (1 unit) transfusion or fibrinogen concentrate (4g) after heparin anticoagulation is reversed. Subjects will be treated only if there is evidence of significant microvascular bleeding. Fifteen minutes after the initial treatment, subjects will be reevaluated for bleeding. If bleeding continues, subjects will be treated with blood transfusion per institutional standard of care. The primary endpoints for this study are the hemostatic condition of the surgical field and 24-hour total of blood product transfusion.

Platelet and plasma transfusion remain in the mainstay hemostatic therapy for perioperative bleeding. Several studies indicate that acquired fibrinogen deficiency can be the primary cause of bleeding after cardiac surgery. The aim of the study is to compare hematologica and transfusion profiles between the first-line fibrinogen replacement and platelet transfusion in post-cardiac surgical bleeding. In this prospective randomized, open-lable study, 20 adult patients undergoing valve replacement or repair, and fulfilling preset visual bleeding scale (0=excellent hemostasis; 1=oozing; 2=moderate bleeding; 3=severe bleeding from multiple bleeding sites) are randomized to 4 g of fibrinogen or 1 unit of apheresis platelet transfusion. After the initial randomized intervention, additional transfusions are given in the presence of bleeding (\>200 ml/hour) according to the institutional practie as follows; 1 apheresis platelet unit if platelet count is less than 100 x 10\^9 /L, 2 units of plasma if international normalized ratio is \>1.6, or 10 units of cryoprecipitate if fibrinogen level is \<200 mg/dL. Primary endpoints include hemostatic condition in the surgical field and 24-hour hemostatic product usage. Hematologica data, clinical outcome, and safety date are collected up to the 28th day postoperative visit.